1. Field of the Invention
The present invention relates generally to extending the life of incandescent light bulbs and, more particularly, to an incandescent light bulb life extending apparatus fixed phase control circuit.
2. Description of the Background
For economy and convenience, many people prefer a light bulb that lasts longer than the standard light bulb.
Standard light bulbs burn out due to the high temperature of a tungsten filament. With standard incandescent light bulbs, the tungsten filament tends to evaporate unevenly. Thinner spots on the tungsten filament are more resistive than the average parts of the filament. With current equal on all parts of the filament, more heat is generated along the thinner spots of the filament. With the thinner spots hotter, these spots tend to evaporate more rapidly than the cooler spots of the filament. This phenomenon increases the speed of the tungsten evaporation along the thinner sports until the thin spot either melts or breaks.
Switching on the power to a standard incandescent light bulb creates another problem. A cold standard incandescent light bulb is less resistive than a hot one. As a result, a standard light bulb draws excessive current until the filament warms up.
Thus, a need exists to extend the life of a standard bulb exists in most homes and businesses. There have been a number of attempts to extend the life of light bulbs within the light bulb itself. Unfortunately, longer lasting light bulbs are expensive, and must be replaced with a longer lasting light bulb to implement an extended light bulb service. The expense of purchasing a longer life light bulb is a severe limitation.
Thus, there remains a need for a simple, comparatively inexpensive reliable means for extending the useful life of existing incandescent light bulbs. However, to be effective a light bulb life extending apparatus must be easy to install and must be cost effective. Moreover, a light bulb life extending apparatus should extend the life of a standard light bulb significantly, when used on a continuous basis. With the foregoing in mind, it would be greatly advantageous to provide a life-extending light bulb apparatus that overcomes these cost and housekeeping problems associated with previous longer light bulbs or systems, by operating with a standard incandescent light bulb.
A number of inventions alter the amount of light emanating from a light source. For example, U.S. Pat. No. 5,017,838 to Nilssen shows a frequency converter that converts 120 Volt/60 Hz received from a power line to an output of 120 Volt/30 kHz, thereby increasing the luminous efficacy. U.S. Pat. No. 6,294,901 to Peron and U.S. Pat. No. 5,789,869 to Lo et al. each show dimmer switch mechanisms.
U.S. Pat. No. 4,980,607 to Albert et al. issued Dec. 25, 1990 shows a light bulb life extender made in a small disc-like form and designed to be removably insertable into a light bulb socket. The device employs a silicon bilateral voltage triggered switch specifically designed to allow a voltage output of a predetermined percentage of the voltage input. Through this reduction in voltage, the associated light bulb will burn slightly less brightly but with significantly extended life span.
While each of the foregoing examples alter the amount of light emanating from a light source either by changing the frequency or by limiting current, none contemplate the use of a phase control circuit. It would be far more advantageous to approach the problem by modifying the A.C. power to the lamp or light fixture using a fixed phase control circuit. This approach would allow the life extending standard light bulb apparatus to accomplish its task without adding complexity to the bulb itself, thereby providing an alternative to expensive longer lasting light bulbs. The inexpensive standard incandescent light bulb would have a significantly extended life, and even then could be replaced with another inexpensive standard incandescent light bulb so that it too could have a significantly extended life without the added cost of purchasing an expensive longer life bulb.